Improvement in chilled mold-boards for plows



NTTED STATES PATENT OFFICE.

JAMES OLIVER, OF SOUTH BEND, INDIANA.

IMPROVEMENT IN CHILLED MOLD-BOARDS FOR PLOWS.

Speciiicaton forming part of Letters Patent No. 1.118,235, dated March3, 1874; application filed January Q9, 1874.

CASE A.

To all whom it may concern:

` Beit known that I, J Arms OLIVER, of South Bend, in the county ot' St.Joseph and State of Indiana,have invented certain new and usefulImprovements in Ohlls for Casting Mold- Boardsi'or Plows; and I dohereby declare that the following is a full, clear, and exactdescription thereof', reference being had to the accompanying drawings,and to the letters of reference marked thereon, which fo rm a part ofthis specilication.

The nature of my invention consists in cast in ggrooves in the backs ofchilled mold-boards, for the purpose of preventing the twisting ot' themold-board in casting, as will be hereinafter more fully set forth.

In order to enable others skilled in the art to which my inventionappertains to make and use the same, I will now proceed to describe themanner in which I accomplish the object, referring to the annexeddrawing, in which- Figure lis a plan viewof flask and chill. Fi g. 2 isa view oi the back of the mold-board.

When melted iron is poured into a ilask containing` a mold-board chill,the iron that is to form the face of the mold-board casting comes indirect contact with the chill, which rapidlyT cools the face of thecasting, thereby chilling or hardeningit to a greater or less depth.This chilling process contracts the face ot the casting, to the depth itis chilled, more than the back of the casting, which is not chilled, in

consequence of which the casting is sprung or warped out of shape to agreater or less extent, depending on the depth to which the metal ischilled. For instance, a mold-board that is chilled half through thethickness of the metal will warp more than one that is chilled twothirds through. This warping makes it diflicult to fit chilledmold-boardsto plow standards and points, and many are un'- iit for useafter casting, while nearly all of them have to be ground, chipped, andiled on the backs, to make them lit properly, before they can be set up.To overcome this warping, I cast grooves in the back oi' the chilledmoldboard castings at the point where they rest on the standards whenset u'p for use.

In the back of the pattern D are made any suitable number fot' grooves,a a, ot' suitable depth, and the pattern, used in the usual manner,producing corresponding grooves in the back of the mold-board. Thesegrooves effectually prevent the mold-boards twisting or'warping,byseparating in several sections that portion ofthe metal which formsthe back or inclined part of the mold-boards, so that the backs, insteadof being of one'piece, to warp or twist by theunequal contraction incooling, have the warp, twist, or strain confined to the narrow sectionsbetween the grooves, thereby breaking the power of the strain, whichotherwise would twist the castings out of shape.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is-

A series of grooves cast in the back of a chilled mold-board for plows,substantially as and for the purposes herein set forth.

In testimony that I claim the foregoing as my own, I aftx Vmy signaturein presence of two witnesses.

JAMES OLIVER.

lVitnesses:

C. H. WATSON, HARRY O. SCOTT.

